medwireNews: Research suggests that all patients aged 60 years or older who have had a stroke, irrespective of the suspected cause, could benefit from enhanced and prolonged monitoring for atrial fibrillation.

The study, Find-AFrandomised, showed Holter-electrocardiogram (ECG) monitoring for 10 days at a median 3.5 days after symptom onset and again at 3 and 6 months detected a 9 percentage point increase in incidences of atrial fibrillation than standard rhythm monitoring for at least 24 hours.

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This detection rate is similar to that previously reported for cryptogenic stroke, notes the team in The Lancet Neurology, and “raises questions about the current practice to only apply prolonged monitoring to patients with cryptogenic stroke.”

Among the 200 patients who were randomly assigned to undergo Holter-ECG monitoring, atrial fibrillation lasting at least 30 seconds was detected in 13.5%. This compared with 4.5% of the 198 patients assigned to receive at least 24 hours of standard monitoring, giving a number needed to screen of 11. The majority of atrial fibrillation episodes were longer than 6 minutes and the median duration of the longest episode was 5 hours.

The study participants included 197 with cryptogenic stroke and 201 with non-cryptogenic, mostly small vessel occlusion and cardioembolic, stroke and there was no difference in atrial fibrillation detection according to stroke subtype. The only subtypes that were excluded prior to randomization were severe ipsilateral carotid and intracranial artery stenosis.

Rolf Wachter (Univeristätsmedizin Göttingen, Germany) and colleagues note that most cases of atrial fibrillation were detected in the first 10 days and there were no recurrences of stroke prior to atrial fibrillation identification within the first 6 months.

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“The detection of atrial fibrillation is of major clinical importance,” remarks the team, and, in accordance with guidelines, it led to oral anticoagulation being initiated in all qualifying patients.

Although the study was not powered to determine the effects of atrial fibrillation monitoring on the reduction of subsequent strokes, the researchers found that the number was numerically lower over the 12-month period for patients receiving Holter-ECG monitoring, at eight versus 14 among those receiving standard monitoring.

Based on their findings, the researchers propose a “stepwise approach” to atrial fibrillation detection. All stroke patients who stand to gain therapeutically from its detection should receive initial Holter-ECG monitoring for 7–10 days within the first days of symptom onset, they suggest. If this initial monitoring is negative, then the individual risk should be assessed and those with suggestive factors, such as repeated cryptogenic strokes, embolic strokes of unknown cause, or frequent supraventricular ectopies, should undergo further intensified monitoring.

However, in a related comment, Fernando Testai (University of Illinois at Chicago Medical Center, USA) cautions against considering stroke as a single entity, irrespective of its pathogenesis, when making treatment decisions based on the occurrence of atrial fibrillation.

“In clinical practice, it is reasonable to offer anticoagulation to patients with radiological evidence of cerebral embolism and atrial fibrillation, even if it is found after the stroke. Whether or not atrial fibrillation is causal or incidental in other stroke subtypes has not yet been determined.”